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<== Date ==> <== Thread ==>
Subject: Re: [EXTERNAL] Difference between caput/caget and PVwrite
From: "Kasemir, Kay via Tech-talk" <tech-talk at aps.anl.gov>
To: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>, Pilar Gil <pilar.gil at sevensols.com>
Date: Tue, 26 Jan 2021 17:31:30 +0000
> ..everything goes well if I set a value using CSS-BOY, but the system runs into a segmentation fault if I use two consecutive times the same variable using caput...

>Which step is CSS-BOY carrying out that caput does not include? 

caput roughly does this:
connect, caget (old value), caput (desired value), caget (new value), disconnect

A display tool like CS-Studio tends to do this:
connect, subscribe to changes (monitor).
When you write, it performs a caput over that standing connection.
No active 'caget', simply relying on the monitor to report the value change that was caused by the 'caput'.
disconnect when you close the display.

So if you experience a problem when calling the command-line caput, maybe it's related to caput calling caget right after writing?

-Kay
References:
Difference between caput/caget and PVwrite Pilar Gil via Tech-talk
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